export default {
  // 为当前模块开启命名空间
  namespaced: true,


  state: () => ({
    // 购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart')||'[]') ,
  }),

  
  mutations: {
    // 添加商品到购物车
    addToCart(state,goods){
      const findResult=state.cart.find((x)=>x.goods_id===goods.goods_id)
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count++
      }
      this.commit('m_cart/saveToStorage')
    },
    // 将购物车中的数据持久化存储到本地
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    // 更新购物车中商品的勾选状态
    updateGoodsState(state,goods){
        const findResult=state.cart.find(x=>x.goods_id===goods.goods_id) 
        if(findResult){
          findResult.goods_state=goods.goods_state
          this.commit('m_cart/saveToStorage')
        }
        
    },
    // 更新购物车中商品的数量
    updateGoodsCount(state,goods){
      const findResult=state.cart.find(x=>x.goods_id===goods.goods_id)
      if(findResult){
        findResult.goods_count=goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    // 根据 Id 从购物车中删除对应的商品信息
    removeGoodsById(state,goods){
      state.cart=state.cart.filter(x=>x.goods_id!==goods.goods_id)
      this.commit('m_cart/saveToStorage')
    },
    // 更新所有商品的勾选状态
    updateAllGoodsState(state,newState){
      state.cart.forEach((good)=>{
        good.goods_state=newState
      })
      this.commit('m_cart/saveToStorage')
    },
  },

  
  getters: {
    // 购物车总数
    total(state){
      let c=0
      state.cart.forEach((item)=>{
        c=item.goods_count+c
      })
      return c
    },
    // 勾选的商品的总数量
    checkedCount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,good)=>total+good.goods_count,0)
    },
    // 已勾选的商品的总价
    checkedGoodsAmount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,good)=>total+good.goods_count*good.goods_price,0).toFixed(2)
    }
  },
}